Method for protection of contactless signal transmission from a transmitter to a receiver, and a signal transmission device

• US 20020034257A1
• Filed: 03/30/2001
• Published: 03/21/2002
• Est. Priority Date: 03/31/2000
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Bergerhoff, Nikolas
• Application Number:
  US09/820,789
• Publication Number:
  US 20020034257A1
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H04K 1/00 Secret communication

Abstract

For contactless signal transmission, a signal transmitted by a transmitter is subjected to reshaping in such a manner that its reproducibility and/or transmissibility are/is exacerbated, but also in ;uch a manner that the reshaping can be detected in a detector in the receiver. In this way, the signal transmission is protected against the possibility of a deliberately short range between the transmitter and receiver being enlarged by manipulation by an intermediate transmitter/receiver.

Claims

1. A method for protection of contactless signal transmission from a transmitter to a receiver, with the signal being subjected to reshaping before being transmitted, such that at least one of reproducibility and transmissibility are exacerbated, and the reshaping can be detected by a detector in the receiver.

2. The method as claimed in claim 1, the signal being subjected to reshaping in a predetermined sequence in time, and detection being carried out in the receiver to determine whether the reshaping is carried out in the predetermined sequence in time.

3. A signal transmission device, comprising:

a transmitter having a reshaping device, which subjects a signal sent from the transmitter for wire-free signal transmission in such a manner that at least one of reproducibility and transmissibility are exacerbated; and

a receiver having a detector which supplies an output signal when reshaping is present.

4. The signal transmission device as claimed in claim 3, the transmitter including a coding device which activates the reshaping device in a predetermined manner in time, and the receiver including a comparison device which checks whether the received signal is preemphasized in the predetermined manner in time.

5. The signal transmission device as claimed in claim 3, the signal transmission taking place by means of electromagnetic waves.

6. The signal transmission device as claimed in claim 3, the reshaping device including a diode which is included in a line between a signal generator and an antenna.

7. The signal transmission device as claimed in claim 3, the receiver including a sensor which converts a magnetic flux density or a magnetic field strength to an electrical voltage or an electrical current.

8. The signal transmission device as claimed in claim 3, the reshaping device including a series circuit, comprising a diode and a differentiation element, in a line between a signal generator and an antenna.